1/8th mile car running a 1/4th mile...RPMs???

[Ron Finney]

Originally Posted by watsongarage

I have an 1/8 mile bracket car. It's a '67 camaro, 2700 lbs. wet, small block , powerglide , 14/32 tires with a 538 gear. Does anybody know what my RPMs might be running a 1/4 mile?

If you know what your 1/8mile ET and MPH is you can determine your approximate 1/4 mile ET and MPH. One quick way to estimate is to look at the index system for the NHRA classes. Once you have an approximate 1/4mi. MPH use the following formula. It will be failry close, will vary some depending on the slippage in your convertor.

rpm = (mph x gear ratio x 336) / tire daimeter.


Hope this helps....
Ron
33 S/C

[MudWild680]

This wont answer your question i dont think..

but another way to find out what your car will run in the 1/4 is to multiply your 1/8 mile time by 1.55

[Dave Goob Cook]

I only gain 400-500 RPM's out the back in the 1/4 over what I'm turning at the 660' mark, but my car is heavier, and slower accelerating than yours, I'm sure.